1. Field of the Invention
The instant disclosure relates to an infrared sensor and manufacturing method thereof; in particular, a miniature infrared sensor and the manufacturing method thereof.
2. Description of Related Art
References are made to FIGS. 1 and 2, which illustrate a conventional infrared sensor having a base 1a, a plurality of pins 2a, a chip 3a, a plurality of wires 4a, a cover 5a, an infrared filter 6a, and a thermistor 7a. 
The base 1a has a plurality of thru holes 11a. The pins 2a are respectively arranged in the thru holes 11a of the base 1a. The chip 3a has a sensing film 31a in the center location thereon and a surrounding wall 32a surrounding the sensing film 31a. The surrounding wall 32a defines a downward-facing opening 321a in the bottom surface of the chip 3a. The surrounding wall 32a is mounted on the base 1a. The thermistor 7a is disposed on the base 1a. Wires 4a connect the upper surface of the surrounding wall 32a and the thermistor 7a to the pins 2a on the base 1a. The cover 5a is mounted on the base 1a to enclose the chip 3a. The cover 5a has a mounting seat 51a located above the sensing film 31a of the chip 3a. The infrared filter 6a is then mounted onto the mounting seat 51a of the cover 5a. 
For the above configuration, a wafer (not shown) having several marked chip patterns is first prepared. Each chip pattern is back-etched to form the concaved structure on the chip. Next, the wafer is cuffed to obtain a plurality of individual chips 3a. 
The chip 3a is then bonded onto the base 1a by a flip chip bonder (not shown). After the pins 2a and the thermistor 7a are set as described earlier, a wire bonder (not shown) is used to wire the chip 3a and the thermistor 7a to the pins 2a respectively. Lastly, the cover 5a having the infrared filter 6a is mounted onto the base 1a to enclose the chip 3a. 
In the conventional infrared sensor, the incoming infrared light passes through the infrared filter 6a and is adsorbed by the sensing film 31a. However, the distance between the infrared filter 6a and the sensing film 31a is often too large, which can lead to light interference known as the crosstalk condition. Further, the conventional sensor must be manufactured individually after individual chips are cut from the wafer. Furthermore, separate processes are required to dispose the pins into the base 1a, to mount the filter 6a onto the cover 5a, and to dispose the thermistor 7a onto the base 1a. Thus, the associated manufacturing cost is high.
Therefore, one aspect of the instant disclosure is to provide an infrared sensor that addresses the aforementioned problems.